NASA's Cassini captured an unexplained Saturn 'glitch' before its fateful dive

NASA's Cassini spacecraft completed its incredibly successful extended mission last week, punctuated by a fiery death at the hands of Saturn's upper atmosphere. But just before the orbiter bid farewell it captured an image of an area of Saturn's rings that scientists still can't fully explain, and it's a tantalizing glimpse at one of the planet's most puzzling features. It's called Peggy, and it's a shifting spot on the edge of one of Saturn's rings that breaks up its otherwise perfect appearanc...